Arctic Liquid Freezer II - FAULTY (Kensington W11)

Hi all - I have had this AIO cooler for a while, but recently it has started to misbehave. It does work sometimes, but other times the pump doesn't seem to be on. It could be that a service and maybe a refill will sort it out. I was going to throw it out, but thought to post it on here in case somebody wants to have a go at fixing it.